     "(phrase [3/3 3/3 2/3 1/3 3/3] ; You can change both the durations and the pitches.
         [ 72  72  72  74  76])"]
    :then
-   ["We can chain together two melodies to make a longer one."
+   ["We can combine two melodies to make a longer one."
     "(->>
   (phrase [3/3 3/3 2/3 1/3 3/3] ; Can you recognise the tune yet?
           [ 72  72  72  74  76])

  (times 2)
  (tempo (bpm 90))) ; Try making the music faster or slower."]
   :key
   ["We have to be careful which pitches we choose. A given piece of music focuses on certain pitches and ignores others. For example, 72 and 74 are in C major, but 73 is not. A convenient way to write songs in-key is to number the notes within the key and then later use code to translate those numbers into specific pitches. Here we use the where function to put each note in C major."
    "(->>
  (phrase [3/3 3/3 2/3 1/3 3/3]
          [  0   0   0   1   2])

    (phrase [2/3 1/3 2/3 1/3 3/3]
            [ 76  74  76  77  79])))"]
   :with
   ["Alternatively, we can play two melodies at the same time. If they're well-chosen, we'll get harmony. If not, we might
    still get something interesting."
   "(->> ; The arrow combines melodies like connect-> combines synthesiser nodes.
  (phrase [3/3 3/3 2/3 1/3 3/3]
          [ 72  72  72  74  76])
  (with
